Per the user's insight: on the secure (Winlogon) desktop the duplication dies on
every independent-flip, and our tight recovery loop tore it down + recreated it
hundreds of times/sec — that release/recreate cycle is the real kernel stress,
and it stalled the send thread long enough that the client timed out ('display
disconnected'). Normal-desktop streaming is already solid (per-session GUID
killed the collision); this only changes the loss-recovery cadence.
Gentle recovery (user chose 'keep session alive'):
- cap the cheap re-duplicate to PUNKTFUNK_RECOVER_MS (default 250ms, was 5ms)
- cap the heavy new-device rebuild to PUNKTFUNK_REBUILD_MS (default 1500ms, was
250ms) — it's the costliest teardown, throttled hardest
- repeat the last frame between attempts (no busy-spin, no 8ms sleep)
~200/s -> ~4/s teardown/recreate during a secure dwell. The session survives
lock/UAC (frozen/laggy secure screen, then clean resume on unlock) instead of
churning the kernel into a disconnect. Both cadences env-tunable.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
enricobuehler
9a9214a2d8